Merging _to_pdf and _to_png to new function _export_as_raster

python-package/lets_plot/export/ggsave_.py

@@ -5,7 +5,7 @@
 from os.path import join
 from typing import Union
 
-from ..plot.core import _to_svg, _to_html, _to_png, _to_pdf
+from ..plot.core import _to_svg, _to_html, _export_as_raster
 from ..plot.core import PlotSpec
 from ..plot.plot import GGBunch
 from ..plot.subplots import SupPlotsSpec
@@ -82,9 +82,9 @@ def ggsave(plot: Union[PlotSpec, SupPlotsSpec, GGBunch], filename: str, *, path:
  elif ext in ['html', 'htm']:
  return _to_html(plot, pathname, iframe=iframe)
  elif ext == 'png':
- return _to_png(plot, pathname, scale)
+ return _export_as_raster(self, path, scale, 'png')
  elif ext == 'pdf':
- return _to_pdf(plot, pathname, scale)
+ return _export_as_raster(self, path, scale, 'pdf')
  else:
  raise ValueError(
  "Unsupported file extension: '{}'\nPlease use one of: 'png', 'svg', 'pdf', 'html', 'htm'".format(ext)

python-package/lets_plot/plot/core.py

@@ -592,7 +592,7 @@ def to_png(self, path, scale: float = None) -> str:
  p.to_png(file_like)
  display.Image(file_like.getvalue())
  """
- return _to_png(self, path, scale)
+ return _export_as_raster(self, path, scale, 'png')
 
  def to_pdf(self, path, scale: float = None) -> str:
  """
@@ -640,7 +640,7 @@ def to_pdf(self, path, scale: float = None) -> str:
  file_like = io.BytesIO()
  p.to_pdf(file_like)
  """
- return _to_pdf(self, path, scale)
+ return _export_as_raster(self, path, scale, 'pdf')
 
 
 class LayerSpec(FeatureSpec):
@@ -823,7 +823,7 @@ def _to_html(spec, path, iframe: bool) -> str | None:
  return None
 
 
-def _to_png(spec, path, scale: float) -> str | None:
+def _export_as_raster(spec, path, scale: float, export_format: str) -> str | None:
  if scale is None:
  scale = 2.0
 
@@ -832,49 +832,30 @@ def _to_png(spec, path, scale: float) -> str | None:
  except ImportError:
  import sys
  print("\n"
- "To export Lets-Plot figure to a PNG file please install CairoSVG library to your Python environment.\n"
+ "To export Lets-Plot figure to a PNG or PDF file please install CairoSVG library"
+ "to your Python environment.\n"
  "CairoSVG is free and distributed under the LGPL-3.0 license.\n"
  "For more details visit: https://cairosvg.org/documentation/\n", file=sys.stderr)
  return None
 
- from .. import _kbridge
- # Use SVG image-rendering style as Cairo doesn't support CSS image-rendering style,
- svg = _kbridge._generate_svg(spec.as_dict(), use_css_pixelated_image_rendering=False)
-
- if isinstance(path, str):
- abspath = _makedirs(path)
- cairosvg.svg2png(bytestring=svg, write_to=abspath, scale=scale)
- return abspath
+ if export_format.lower() == 'png':
+ export_function = cairosvg.svg2png
+ elif export_format.lower() == 'pdf':
+ export_function = cairosvg.svg2pdf
  else:
- cairosvg.svg2png(bytestring=svg, write_to=path, scale=scale)
- return None
-
-
-def _to_pdf(spec, path, scale: float) -> str | None:
- if scale is None:
- scale = 2.0
-
- try:
- import cairosvg
- except ImportError:
- import sys
- print("\n"
- "To export Lets-Plot figure to a PDF file please install CairoSVG library to your Python environment.\n"
- "CairoSVG is free and distributed under the LGPL-3.0 license.\n"
- "For more details visit: https://cairosvg.org/documentation/\n", file=sys.stderr)
- return None
+ raise ValueError("Unknown export format: {}".format(export_format))
 
  from .. import _kbridge
  # Use SVG image-rendering style as Cairo doesn't support CSS image-rendering style,
  svg = _kbridge._generate_svg(spec.as_dict(), use_css_pixelated_image_rendering=False)
 
  if isinstance(path, str):
  abspath = _makedirs(path)
- cairosvg.svg2pdf(bytestring=svg, write_to=abspath, scale=scale)
- return abspath
+ result = abspath
  else:
- cairosvg.svg2pdf(bytestring=svg, write_to=path, scale=scale)
- return None
+ result = None # file-like object is provided. No path to return.
+ export_function(bytestring=svg, write_to=path, scale=scale)
+ return result
 
 
 def _makedirs(path: str) -> str:

python-package/lets_plot/plot/subplots.py

@@ -11,7 +11,7 @@
 from lets_plot.plot.core import FeatureSpecArray
 from lets_plot.plot.core import _specs_to_dict
 from lets_plot.plot.core import _theme_dicts_merge
-from lets_plot.plot.core import _to_svg, _to_html, _to_png, _to_pdf
+from lets_plot.plot.core import _to_svg, _to_html, _export_as_raster
 
 __all__ = ['SupPlotsSpec']
 
@@ -244,7 +244,7 @@ def to_png(self, path, scale=None) -> str:
  p.to_png(file_like)
  display.Image(file_like.getvalue())
  """
- return _to_png(self, path, scale)
+ return _export_as_raster(self, path, scale, 'png')
 
  def to_pdf(self, path, scale=None) -> str:
  """
@@ -291,4 +291,4 @@ def to_pdf(self, path, scale=None) -> str:
  file_like = io.BytesIO()
  p.to_pdf(file_like)
  """
- return _to_pdf(self, path, scale)
+ return _export_as_raster(self, path, scale, 'pdf')